How to decelerate a 2D object?

I have a simple 2D object that I want to slowly decelerate before it stops.
This is the script that is attached to the object (it’s just the basic movement):

void Update () {
	float horizontal = Input.GetAxis ("Horizontal");
	float vertical = Input.GetAxis ("Vertical");
	Vector3 move = new Vector3 (horizontal, vertical, 0.0f);

	transform.position += move * speed * Time.deltaTime;


you need to detect if your Vector3 is zero (if the player has released) the input and interpolate to zero then.
Something like this :

private Vector2 _input;
private Vector3 _move;
void Update ()
    _input = new Vector2 (Input.GetAxis ("Horizontal"), Input.GetAxis ("Vertical"));
    if (_input !=
        _move = (Vector3) _input;
         _move = Vector3.Lerp (_move,, decelerationSpeed * Time.deltaTime);
    transform.Translate (_move * speed * Time.deltaTime);